/Engine/Source/Developer/SourceControl/Public/ISourceControlState.h
Get head modification information for other branches
true with parameters populated if there is a branch with a newer modification (edit/delete/etc)
bool GetOtherBranchHeadModification ( [FString](API\Runtime\Core\Containers\FString) & HeadBranchOut, [FString](API\Runtime\Core\Containers\FString) & ActionOut, int32 & HeadChangeListOut ) const